JP2010267536A - Polymer electrolyte fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer electrolyte fuel cell capable of restraining poisoning of catalyst, by absorbing/capturing impurities of organic matters or the like with oil absorption bodies. <P>SOLUTION: The polymer electrolyte fuel cell is provided with an electrolyte layer-electrode assembly 5 having an electrolyte layer 1 arranged between a pair of electrodes 4A, 4B, a pair of annular gaskets 6A, 6B arranged so as to surround the pair of electrodes 4A, 4B, a pair of conductive separators 7A, 7B arranged so as to pinch the electrolyte layer-electrode assembly 5 and the pair of gaskets 6A, 6B and with groove-shaped reaction gas flow channels 11, 12 formed for flowing reaction gas on one of the main faces in contact with the electrodes 4A, 4B, and oil absorption bodies 8A, 8B fitted at least at a part of one of the main faces of the separators 7A, 7B. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a structure of a polymer electrolyte fuel cell, and particularly to a structure of a separator.

  A polymer electrolyte fuel cell (hereinafter referred to as PEFC) generates electric power and heat simultaneously by electrochemically reacting a fuel gas containing hydrogen and an oxidant gas containing oxygen such as air. is there. A single cell (cell) of PEFC is composed of a polymer electrolyte membrane and a pair of gas diffusion electrodes (anode and cathode), a MEA (Membrane-Electrode-Assembly), a gasket, and a conductive material. And a plate-like separator. The PEFC is generally formed by stacking a plurality of cells, sandwiching both ends of the stacked cells with end plates, and fastening the end plates and the cells with fasteners.

  By the way, PEFC is composed of various types of resin materials, and additional components such as flame retardants, mold release agents and lubricants (a small amount of organic substances and ions such as sulfite ions) are used to react with moisture in the reaction gas and electrochemical reaction. Thus, there is a problem that the catalyst is made of platinum and an alloy containing platinum which is eluted by elution into the generated water produced to reach the gas diffusion electrode. In addition, there is a problem that the power generation performance is remarkably deteriorated because the eluted organic substance is adsorbed on the pores of the carbon material constituting the catalyst layer to inhibit mass transfer.

  For such problems, a polymer electrolyte fuel cell (for example, refer to Patent Document 1) in which a gasket is pretreated such as cleaning or heat treatment, or a polymer electrolyte fuel cell in which a trapping agent is mixed in a separator (for example, Patent Document 2) is known. In the polymer electrolyte fuel cell disclosed in Patent Document 1, pretreatment such as cleaning and heat treatment is performed on the gasket to control the components eluted from the gasket and the amount thereof, thereby suppressing poisoning of the catalyst. Thus, it is possible to suppress the performance degradation of the fuel cell. In addition, in the polymer electrolyte fuel cell disclosed in Patent Document 2, organic substances and ions eluted from the binder resin of the separator are captured by a trapping agent, and the elution is suppressed, thereby reducing the performance of the fuel cell. Can be suppressed.

JP 2005-26104 A JP 2004-235034 A

  However, in the polymer electrolyte fuel cells disclosed in Patent Document 1 and Patent Document 2, sufficient battery performance is exhibited due to material selection restrictions and construction method restrictions in order to suppress catalyst poisoning. There have been problems such as being unable to do so and incurring an increase in cost, and inadequate function for blocking the eluted organic substances.

  That is, in the polymer electrolyte fuel cell disclosed in Patent Document 1, if the additive to the resin is limited by the presence or absence of the eluted component, the function that can be added to the resin is limited, and sufficient battery performance is achieved. There was a problem that it was impossible to design a battery that could be used. In addition, pretreatment such as heat treatment and cleaning has a problem that the manufacturing cost increases.

  Further, in the polymer electrolyte fuel cell disclosed in Patent Document 2, it is necessary to provide a trapping material on all of the elution surfaces of the members, so that the direct material cost increases, and the trapping material is used for a gas seal portion or the like. Therefore, the function of blocking the eluted organic substance from reaching the catalyst layer may be insufficient.

  On the other hand, in order to suppress poisoning of the catalyst, it is conceivable to use a high-grade material with few impurities as the constituent material, but generally a clean material with high purity is expensive and the direct material cost increases. Will do. Further, in a design using a material having a low function, it is often necessary to supplement a low function by increasing the amount of use of the material, which increases the cost of direct materials.

  The present invention has been made in view of such problems, and provides a polymer fuel cell that is inexpensive and has high power generation performance without being restricted by the elution component of a resin material used as a gasket. Objective.

  In order to solve the above problems, a polymer electrolyte fuel cell according to the present invention sandwiches an electrolyte layer and a portion excluding the peripheral portion of the electrolyte layer, and includes a gas diffusion layer, the gas diffusion layer, and the electrolyte layer, respectively. An electrolyte layer-electrode assembly having a pair of electrodes including a catalyst layer disposed between the electrodes, a pair of annular gaskets disposed so as to surround the pair of electrodes, and a plate shape, the electrolyte A pair of conductive separators disposed so as to sandwich the layer-electrode assembly and the pair of gaskets, and having a groove-like reaction gas channel in which a reaction gas flows on one main surface in contact with the electrode And an oil absorber provided on at least a part of one main surface of the separator.

  Thereby, impurities, such as organic substance eluted from the gasket, can be absorbed and captured by the oil absorber.

  In the polymer electrolyte fuel cell according to the present invention, a groove may be provided on at least a part of one main surface of the separator, and the oil absorber may be provided in the groove.

  In the polymer electrolyte fuel cell according to the present invention, the oil absorber may be provided in an outer portion than the catalyst layer on one main surface of the separator as viewed from the thickness direction of the separator. Good.

  In the polymer electrolyte fuel cell according to the present invention, the oil absorber may be provided between the catalyst layer and the gasket.

  In the polymer electrolyte fuel cell according to the present invention, the oil absorber is provided on at least a part of a portion of the one main surface of the separator facing the gasket as viewed from the thickness direction of the separator. May be.

  Further, in the polymer electrolyte fuel cell according to the present invention, the oil absorber may be provided over the entire portion of the one main surface of the separator facing the gasket as viewed from the thickness direction of the separator. .

  Furthermore, in the polymer electrolyte fuel cell according to the present invention, the oil absorber includes one or more substances selected from the group consisting of polypropylene fiber, polyethylene fiber, polystyrene fiber, urethane foam, kapok fiber, and silica gel. It is preferable that it is comprised.

  According to the polymer electrolyte fuel cell of the present invention, even if an inexpensive material is used, poisoning of the catalyst can be suppressed by absorbing and capturing impurities such as organic substances with the oil absorber.

FIG. 1 is a perspective view schematically showing a schematic configuration of a polymer electrolyte fuel cell according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view schematically showing a schematic configuration of a cell in the polymer electrolyte fuel cell shown in FIG. FIG. 3 is a perspective view of the cell shown in FIG. 2 as viewed from the thickness direction. FIG. 4 is a cross-sectional view schematically showing a schematic configuration of a cell in the polymer electrolyte fuel cell according to Embodiment 2 of the present invention. FIG. 5 is a perspective view of the cell shown in FIG. 4 as viewed from the thickness direction. FIG. 6 is a perspective view schematically showing a schematic configuration of a cell in the polymer electrolyte fuel cell according to Embodiment 3 of the present invention. FIG. 7 is a cross-sectional view schematically showing a schematic configuration of a cell in a polymer electrolyte fuel cell according to Embodiment 4 of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

(Embodiment 1)
[Configuration of polymer electrolyte fuel cell]
FIG. 1 is a perspective view schematically showing a schematic configuration of a polymer electrolyte fuel cell according to Embodiment 1 of the present invention. In FIG. 1, the vertical direction in the polymer electrolyte fuel cell is shown as the vertical direction in the figure.

  As shown in FIG. 1, the polymer electrolyte fuel cell 100 according to Embodiment 1 of the present invention is configured by a fuel cell stack having a cell stack 70 in which a plurality of cells 10 are stacked. The polymer electrolyte fuel cell 100 includes, for example, a cell stack 70, end plates 71A and 71B disposed at both ends of the cell stack 70, and cell stack 70 and end plates 71A and 71B in a cell stacking direction. And a fastener (not shown) for fastening. An insulating plate 72A and a current collector plate 73A are disposed between the end plate 71A and the cell stack 70. Similarly, an insulating plate 72B and a current collector plate 73B are disposed between the end plate 71B and the cell stack 70.

  The cell stack 70 is provided with a fuel gas supply manifold, an oxidant gas supply manifold, a coolant supply manifold, a fuel gas discharge manifold, an oxidant gas discharge manifold, and a coolant discharge manifold (all not shown). ). The end plate 71A, the insulating plate 72A, and the current collecting plate 73A are provided with through holes corresponding to (communicating with) each manifold such as a fuel gas supply manifold. In the through holes corresponding to the manifolds such as the fuel gas supply manifold of the end plate 71A, the fuel gas supply path 81, the cooling medium supply path 82, the oxidant gas supply path 83, the fuel gas discharge path 84, and the cooling are respectively provided. A medium discharge path 85 and an oxidant gas discharge path 86 are connected. As a result, fuel gas or the like is supplied to the polymer electrolyte fuel cell 100, and fuel gas or the like that has not been used is discharged from the polymer electrolyte fuel cell 100.

[Cell structure]
Next, the configuration of the cell 10 in the polymer electrolyte fuel cell 100 according to Embodiment 1 will be described with reference to FIGS.

  FIG. 2 is a cross-sectional view schematically showing a schematic configuration of the cell 10 in the polymer electrolyte fuel cell 100 shown in FIG. FIG. 3 is a perspective view of the cell 10 shown in FIG. 2 as viewed from the thickness direction. 2 and 3, the vertical direction in the cell 10 is represented as the vertical direction in the drawings. In FIG. 3, the fuel gas flow path, the oxidant gas flow path, the cooling medium flow path, and one of the gaskets are omitted, and the oil absorbing body is indicated by hatching.

  As shown in FIGS. 2 and 3, the cell 10 in the polymer electrolyte fuel cell 100 according to the first embodiment includes a MEA (Membrane-Electrode-Assembly) 5 and a pair of gaskets. 6A, 6B, a pair of separators 7A, 7B, and oil absorbers 8A, 8B.

  The MEA 5 has a pair of electrodes 4A and 4B and an electrolyte layer 1 disposed between the pair of electrodes 4A and 4B. In the first embodiment, the electrode 4A constitutes the anode 4A, and the electrode 4B constitutes the cathode 4B. As the electrolyte layer 1, for example, a polymer electrolyte membrane that selectively transports hydrogen ions (for example, Nafion (trade name) manufactured by DuPont, USA) can be used.

  In the first embodiment, the electrolyte layer 1 has a substantially quadrangular (here, rectangular) shape. An anode 4A and a cathode 4B are respectively disposed on both surfaces of the electrolyte layer 1 so as to be located inward from the peripheral edge. In addition, in the peripheral portion of the electrolyte layer 1, a fuel gas supply manifold hole 51, a cooling medium supply manifold hole 52, an oxidant gas supply manifold 53, a fuel gas discharge manifold hole 54, a cooling medium discharge manifold hole 55, and an oxidant gas. A discharge manifold hole 56 is provided so as to penetrate in the thickness direction (see FIG. 3).

  The anode 4A is provided on one main surface of the electrolyte layer 1, and is a mixture of conductive carbon particles carrying an electrode catalyst (for example, platinum and an alloy containing platinum) and a polymer electrolyte having hydrogen ion conductivity. And an anode gas diffusion layer 3A that is provided on the main surface of the anode catalyst layer 2A and has both gas permeability and conductivity. Similarly, the cathode 4B is provided on the other main surface of the electrolyte layer 1, and includes conductive carbon particles carrying an electrode catalyst (for example, platinum and an alloy containing platinum), and a polymer electrolyte having hydrogen ion conductivity. And a cathode gas diffusion layer 3B provided on the main surface of the cathode catalyst layer 2B and having both gas permeability and conductivity.

  The anode catalyst layer 2A and the cathode catalyst layer 2B use a catalyst layer forming ink containing conductive carbon particles carrying an electrode catalyst made of platinum and an alloy containing platinum, a polymer electrolyte, and a dispersion medium. And can be formed by methods known in the art. The material constituting the anode gas diffusion layer 3A and the cathode gas diffusion layer 3B is not particularly limited, and materials known in the art can be used. For example, conductive materials such as carbon cloth and carbon paper can be used. A porous porous substrate can be used. In addition, the conductive porous substrate may be subjected to water repellent treatment by a conventionally known method.

  In addition, a pair of annular gaskets 6A and 6B are sandwiched around the electrolyte layer 1 around the anode 4A and the cathode 4B of the MEA 5 (more precisely, outside the anode gas diffusion layer 3A (cathode gas diffusion layer 3B)). It is arranged. The gaskets 6A and 6B have, for example, an electrode peripheral portion 60 surrounding the anode 4A and the cathode 4B, and manifold hole peripheral portions 61 to 66 surrounding each manifold hole. Here, the electrode surrounding portion 60 is formed in a substantially rectangular shape, and the manifold hole surrounding portions 61 to 66 are formed in an oval shape. And manifold hole peripheral parts 61-66 are connected to the electrode peripheral part 60, respectively. In the present embodiment, each of the gaskets 6A and 6B has a configuration in which the manifold hole peripheral portions 61 to 66 are connected to the electrode peripheral portion 60. However, the present invention is not limited to this. 60 and the manifold hole peripheral portions 61 to 66 may not be connected, or the manifold hole peripheral portions 61 to 66 may be connected to each other.

  In the gasket 6A disposed on the anode 4A side, the second gas in the manifold hole peripheral portion 61 is supplied so that the fuel gas can be supplied from the fuel gas supply manifold hole 51 to a fuel gas flow path 11 (see FIG. 2) described later. The side part side opening is opened. Further, in the gasket 6 </ b> A, the side portion on the first side portion side of the manifold hole peripheral portion 64 is opened so that fuel gas or the like that has not been used in the fuel gas discharge manifold hole 54 can be discharged from the fuel gas passage 11. ing. Similarly, in the gasket 6 </ b> B, a side portion on the first side portion side of the manifold hole peripheral portion 63 is opened so that the oxidizing gas can be supplied to the oxidizing gas channel 12. The side part on the second side part side of the manifold hole peripheral part 66 is opened so that the agent gas can be discharged. Thereby, it is suppressed that fuel gas and oxidant gas leak out of the cell 10, and these gases are suppressed from being mixed with each other in the polymer electrolyte fuel cell 100.

  As a material constituting the gaskets 6A and 6B, for example, a compound such as a rubber material, a thermoplastic elastomer, or an adhesive can be used. Specific examples of the sealing material constituting the gasket include fluorine rubber, silicone rubber, natural rubber, EPDM, butyl rubber, butyl chloride rubber, butyl bromide rubber, butadiene rubber, styrene-butadiene copolymer, ethylene-vinyl acetate rubber, acrylic rubber, poly Adhesive using thermoplastic elastomer such as isopropylene polymer, perfluorocarbon, polystyrene, polyolefin, polyester and polyamide, or latex such as isoprene rubber and butadiene rubber, liquid polybutadiene, polyisoprene, polychloroprene, silicone Examples of the adhesive include rubber, fluororubber, and acrylonitrile-butadiene rubber, but are not limited to these compounds. These compounds may be used alone or in combination of two or more.

  Gaskets 6 </ b> A and 6 </ b> B are prevented from leaking fuel gas and oxidant gas outside cell 10, and are prevented from being mixed with each other in polymer electrolyte fuel cell 100. If it is, the shape is arbitrary.

  Also, a pair of conductive plate-like separators 7A and 7B are disposed so as to sandwich the MEA 5 and the gaskets 6A and 6B. Thereby, MEA 5 is mechanically fixed, and when a plurality of cells 10 are stacked in the thickness direction, MEA 5 is electrically connected. In addition, these separators 7A and 7B can use the metal excellent in heat conductivity and electroconductivity, graphite, or what mixed graphite and resin, for example, carbon powder and a binder (solvent). A mixture prepared by injection molding or a plate of titanium or stainless steel plated with gold can be used.

  On one main surface (hereinafter referred to as an inner surface) of the separator 7A that is in contact with the anode 4A, a groove-like fuel gas flow path 11 for allowing the fuel gas to flow is provided, and the other main surface ( A groove-like cooling medium flow path 13 through which the cooling medium flows is provided on the outer surface). Similarly, a groove-like oxidant gas flow path 12 through which an oxidant gas flows is provided on one main surface (hereinafter referred to as an inner surface) of the separator 7B that contacts the cathode 4B. The other main surface (hereinafter referred to as an outer surface) is provided with a groove-like coolant flow path 13 through which the coolant flows. In addition, each manifold hole such as the fuel gas supply manifold hole 51 is provided in the peripheral portion of the main surface of the separators 7A and 7B (see FIG. 3).

  Thereby, fuel gas and oxidant gas are supplied to the anode 4A and the cathode 4B, respectively, and these gases react to generate electricity and heat. Further, the generated heat is recovered by passing a cooling medium such as cooling water through the cooling medium flow path 13.

  Oil separators 8A and 8B are provided on the inner surfaces of the separators 7A and 7B, respectively. Specifically, the oil absorbing body 8A has a portion outside the anode catalyst layer 2A on the inner surface of the separator 7A as viewed from the thickness direction of the separator 7A (outside a portion facing the anode catalyst layer 2A on the inner surface of the separator 7A). Is provided on the side). More specifically, the oil absorbing body 8A is provided between the gasket 6A and the anode catalyst layer 2A on the inner surface of the separator 7A, and is provided so as to surround the anode catalyst layer 2A as a whole.

  Similarly, the oil absorbing body 8B is a portion outside the cathode catalyst layer 2B on the inner surface of the separator 7B when viewed from the thickness direction of the separator 7B (an outer portion than a portion facing the cathode catalyst layer 2B on the inner surface of the separator 7B). ). More specifically, the oil absorber 8B is provided between the gasket 6B and the cathode catalyst layer 2B on the inner surface of the separator 7B, and is provided so as to surround the cathode catalyst layer 2B as a whole.

  Here, the “outer part than the catalyst layer on the inner surface of the separator” means an outer side than the part including the end (here, the peripheral surface) of the catalyst layer on the inner surface of the separator as viewed from the thickness direction of the separator. In other words, it is the peripheral edge of the inner surface of the separator. “The oil absorber is provided between the gasket and the catalyst layer” means that the oil absorber is not only provided in the space formed between the gasket and the catalyst layer, but also in contact with the gasket or the catalyst layer. (See FIG. 3). In addition, it is preferable that the oil absorber is provided so as not to come into contact with the catalyst layer because the risk of electrolytic corrosion due to the potential decreases.

  Further, “so as to enclose as a whole” is a range in which the oil absorbing body 8A and part of the oil absorbing body 8B do not surround the anode catalyst layer 2A and the cathode catalyst layer 2B, respectively, within the range where the effects of the present invention are exhibited. I say that you may have.

  The material constituting the oil absorbent bodies 8A and 8B is a group of substances consisting of polypropylene fiber, polyethylene fiber, polystyrene fiber, urethane foam, kapok fiber, and silica gel from the viewpoint of efficiently absorbing a small amount of organic matter eluted from the gaskets 6A and 6B. It is preferable to include one or more substances selected from:

  The material constituting the oil absorbent bodies 8A and 8B is preferably a porous and highly absorbent material from the viewpoint of efficiently absorbing a small amount of organic matter eluted from the gaskets 6A and 6B. For example, activated carbon, activated carbon fiber One or more substances selected from the group consisting of molecular sieve carbon, silica gel, activated alumina, zeolite, oil-absorbing polymer, and organic adsorbent may be included. Examples of the organic adsorbent include styrene-divinylbenzene, methacrylic acid ester, vinyl pyridine and the like, but are not particularly limited to these compounds. Further, the oil absorbing bodies 8A and 8B may have an oil absorption amount larger than the total amount of additives added to the gaskets 6A and 6B from the viewpoint of preventing the oil absorbing performance from being lost even when used for a long time. preferable.

  Further, the oil absorbent bodies 8A and 8B are made more hydrophilic than at least one of the anode gas diffusion layer 3A, the cathode gas diffusion layer 3B, the gaskets 6A and 6B, and the separators 7A and 7B (so that the hydrophilicity becomes higher). ) Are preferably configured, and more preferably configured to be more hydrophilic than these components. The organic substances eluted from the gaskets 6A and 6B reach the anode catalyst layer 2A and the cathode catalyst layer 2B through the dew condensation water and the generated water. For this reason, since the water containing the eluted organic substance selectively passes through the oil absorbing bodies 8A and 8B by making the hydrophilicity of the oil absorbing bodies 8A and 8B higher than that of the adjacent member, the effect of removing the organic substances is enhanced. Can do.

  In addition, as a method for increasing hydrophilicity, when using a porous and highly oil-absorbing substance such as activated carbon as the oil absorbent bodies 8A and 8B, titanium oxide or a polymer electrolyte (for example, US DuPont (for example, There is a method of mixing a highly hydrophilic material such as Nafion (trade name) manufactured by Co., Ltd. There is also a method of improving hydrophilicity by modifying the surface of the material constituting the oil absorbent bodies 8A and 8B by oxygen plasma or ozone treatment. Furthermore, when using a powdery oil-absorbing material, an electrolyte can be used as a binder, as with the catalyst layer. From the viewpoint of increasing the hydrophilicity, it is better to increase the ratio of the electrolyte to the powdery oil-absorbing material. preferable. If the ratio of the electrolyte is increased, the gas diffusibility of the oil absorbers 8A and 8B can be reduced, so that the oil absorption capacity is wasted due to impurity components contained in the fuel gas and oxidant gas supplied from the outside. Can be suppressed.

  Moreover, as a preparation method in the case of using a porous and highly oil-absorbing substance such as the activated carbon as the oil absorbent bodies 8A and 8B, for example, a paste prepared by mixing activated carbon powder and perfluorocarbon sulfonic acid is prepared, It may be created using a screen printing method, or may be created by punching a nonwoven fabric made of activated carbon fibers in a ring shape.

  In the polymer electrolyte fuel cell 100 according to the first embodiment configured as described above, a small amount of organic matter eluted from the gaskets 6A and 6B is absorbed in the oil absorber 8A before reaching the anode catalyst layer 2A or the cathode catalyst layer 2B. , 8B is absorbed and captured. For this reason, it is suppressed that the electrode catalyst (for example, platinum and the alloy containing platinum) of anode catalyst layer 2A and cathode catalyst layer 2B is poisoned, and carbon which constitutes anode catalyst layer 2A and cathode catalyst layer 2B Since the pores of the material are prevented from being blocked, high battery performance can be maintained.

  In the first embodiment, the oil absorber 8A is provided between the anode catalyst layer 2A and the gasket 6A, and the oil absorber 8B is provided between the cathode catalyst layer 2B and the gasket 6B. It is not limited, It is good also as a structure which provides an oil-absorbing body between one catalyst layer and a gasket. In addition, the oil absorbing bodies 8A and 8B are provided so as to surround the anode catalyst layer 2A and the cathode catalyst layer 2B as a whole as viewed from the thickness direction of the electrolyte layer 1, but the present invention is not limited thereto. The shape is not limited as long as it is provided between the layer and the gasket.

  In the first embodiment, the fuel cell stack is formed by stacking a plurality of cells 10. However, the present invention is not limited to this, and the fuel cell stack may be formed by one cell 10.

(Embodiment 2)
FIG. 4 is a cross-sectional view schematically showing a schematic configuration of a cell in the polymer electrolyte fuel cell according to Embodiment 2 of the present invention. FIG. 5 is a perspective view of the cell shown in FIG. 4 as viewed from the thickness direction. 4 and 5, the vertical direction in the cell is represented as the vertical direction in the figure. In FIG. 5, the fuel gas passage, the oxidant gas passage, the cooling medium passage, and one of the gaskets are omitted, and the oil absorbing body is indicated by hatching.

  As shown in FIGS. 4 and 5, the polymer electrolyte fuel cell 100 according to Embodiment 2 of the present invention has the same basic configuration as the polymer electrolyte fuel cell 100 according to Embodiment 1. The oil absorbent bodies 8A and 8B are different in that they are disposed (provided) in the groove portions 9A and 9B provided on the inner surfaces of the separators 7A and 7B, respectively.

  Specifically, the groove 9A is provided between the gasket 6A and the anode catalyst layer 2A on the inner surface of the separator 7A, and is provided so as to surround the anode catalyst layer 2A as a whole. Similarly, the groove 9B is provided between the gasket 6B and the cathode catalyst layer 2B on the inner surface of the separator 7B, and is provided so as to surround the cathode catalyst layer 2B as a whole. And the oil absorption bodies 8A and 8B are arrange | positioned at the groove parts 9A and 9B comprised in this way.

  Even the polymer electrolyte fuel cell 100 according to the second embodiment configured as described above has the same effects as the polymer electrolyte fuel cell 100 according to the first embodiment. In the polymer electrolyte fuel cell 100 according to the second embodiment, the oil absorbers 8A and 8B are disposed in the grooves 9A and 9B, respectively. Therefore, when the polymer electrolyte fuel cell 100 is assembled, The oil absorbers 8A and 8B can be easily positioned. In addition, a small amount of organic substances eluted from the gaskets 6A and 6B can be trapped by the grooves 9A and 9B, and are prevented from reaching the anode catalyst layer 2A and the cathode catalyst layer 2B through the inner surfaces of the separators 7A and 7B. Further, the poisoning of the electrode catalyst (for example, platinum and an alloy containing platinum) of the anode catalyst layer 2A and the cathode catalyst layer 2B is suppressed, and the carbon material constituting the anode catalyst layer 2A and the cathode catalyst layer 2B. It is further suppressed that the pores are blocked. For this reason, in the polymer electrolyte fuel cell 100 according to Embodiment 2, it is possible to maintain higher cell performance.

(Embodiment 3)
FIG. 6 is a perspective view schematically showing a schematic configuration of a cell in the polymer electrolyte fuel cell according to Embodiment 3 of the present invention. In FIG. 6, the vertical direction in the cell is represented as the vertical direction in the drawing, and the fuel gas channel, the oxidant gas channel, the cooling medium channel, one gasket and the oil absorber are omitted, and the oil absorber is Shown by hatching.

  As shown in FIG. 6, the basic structure of the polymer electrolyte fuel cell 100 according to the third embodiment is the same as that of the polymer electrolyte fuel cell 100 according to the first embodiment. The oil absorbing body 8B (not shown in FIG. 6) is different in that it is opened. Specifically, the oil absorber 8A is a portion between the anode catalyst layer 2A and the gasket 6A, and a portion between the fuel gas discharge manifold hole 54 and the anode catalyst layer 2A is provided with the oil absorber 8A. Is configured to not. Similarly, the oil absorber 8B is a portion between the cathode catalyst layer 2B and the gasket 6B, and a portion between the oxidant gas discharge manifold hole 56 and the cathode catalyst layer 2B is not provided with the oil absorber 8B. It is configured as follows.

  That is, the oil absorber 8A is provided so as to surround the anode catalyst layer 2A so that a portion between the fuel gas discharge manifold hole 54 and the anode catalyst layer 2A becomes an opening portion. Similarly, the oil absorber 8B is provided so as to surround the cathode catalyst layer 2B so that a portion between the oxidant gas discharge manifold hole 56 and the cathode catalyst layer 2B becomes an opening portion.

  As in the vicinity of the fuel gas discharge manifold hole 54, in the portion where the fuel gas, water vapor, and water flow from the anode catalyst layer 2A to the outside of the cell 10, the organic substance that has eluted is not dissolved even if the organic substance is eluted from the gasket 6A. The gas is discharged out of the cell 10 along the flow of fuel gas or the like. The same applies to the vicinity of the oxidant gas discharge manifold hole 56. Therefore, the oil absorbers 8A and 8B are not provided in the portion between the fuel gas discharge manifold hole 54 and the anode catalyst layer 2A or in the portion between the oxidant gas discharge manifold hole 56 and the cathode catalyst layer 2B. However, there is little possibility that the anode catalyst layer 2A is poisoned.

  Therefore, even the polymer electrolyte fuel cell 100 according to the third embodiment configured as described above has the same effects as the polymer electrolyte fuel cell 100 according to the first embodiment.

(Embodiment 4)
FIG. 7 is a cross-sectional view schematically showing a schematic configuration of a cell in a polymer electrolyte fuel cell according to Embodiment 4 of the present invention. In FIG. 7, the vertical direction in the cell is represented as the vertical direction in the figure.

  As shown in FIG. 7, the polymer electrolyte fuel cell 100 according to the fourth embodiment of the present invention has the same basic configuration as the polymer electrolyte fuel cell 100 according to the second embodiment. The difference is that a frame member 14 is provided so as to sandwich the periphery of the electrolyte layer 1.

  Specifically, the frame member 14 is formed in a substantially rectangular ring shape, and is joined to the outer edge of the electrolyte layer 1 of the MEA 5. The opening of the frame member 14 is formed to be slightly larger than the anode 4A or the cathode 4B of the MEA 5. Further, each manifold hole such as a fuel gas supply manifold hole is provided in the peripheral portion of the frame member 14. Furthermore, positioning grooves 14A and 14B for facilitating positioning of the gaskets 6A and 6B are formed on the main surface of the frame member 14.

  Further, the groove portions 9A and 9B provided in the separators 7A and 7B are formed so as to overlap the gaskets 6A and 6B when viewed from the thickness direction of the separators 7A and 7B. And oil-absorbing bodies 8A and 8B are positioned in the grooves 9A and 9B, respectively.

  Furthermore, the gaskets 6A and 6B have fitting portions 16A and 16B, respectively, and these fitting portions 16A and 16B are fitted in the positioning grooves 14A and 14B. The gaskets 6A and 6B are formed with dimensions slightly larger than the widths of the groove portions 9A and 9B. When the polymer electrolyte fuel cell 100 is fastened, the gaskets 6A and 6B are pressed to form the groove portions 9A and 7B of the separators 7A and 7B. It is comprised so that it may fit in 9B. Thereby, gasket 6A, 6B can seal the circumference | surroundings of each manifold hole and MEA5 more appropriately.

  Even the polymer electrolyte fuel cell 100 according to the fourth embodiment configured as described above has the same effects as the polymer electrolyte fuel cell 100 according to the second embodiment. Further, in the polymer electrolyte fuel cell 100 according to the fourth embodiment, the oil absorbing bodies 8A and 8B are provided in portions facing the gaskets 6A and 6B when viewed from the thickness direction of the separators 7A and 7B. A small amount of organic substances eluted from the gaskets 6A and 6B can be absorbed and captured by the oil absorbent bodies 8A and 8B. Electrode catalysts (for example, platinum and platinum-containing alloys) of the anode catalyst layer 2A and the cathode catalyst layer 2B Since poisoning is further suppressed and the pores of the carbon material constituting the anode catalyst layer 2A and the cathode catalyst layer 2B are further blocked, the high battery performance is further maintained. Is possible.

  The polymer electrolyte fuel cell of the present invention can suppress poisoning of the catalyst by absorbing and trapping impurities such as organic substances with an oil absorber even if an inexpensive material is used. Useful in the technical field.

DESCRIPTION OF SYMBOLS 1 Electrolyte layer 2A Anode catalyst layer 2B Cathode catalyst layer 3A Anode gas diffusion layer 3B Cathode gas diffusion layer 4A Electrode (anode)
4B electrode (cathode)
5 MEA (Membrane-Electrode-Assembly: Electrolyte layer-electrode assembly)
6A gasket 6B gasket 7A separator 7B separator 8A oil absorber 8B oil absorber 9A groove 9B groove 10 cell 11 fuel gas flow channel 12 oxidant gas flow channel 13 cooling medium flow channel 14 frame member 14A positioning groove 14B positioning groove 16A fitting portion 16B Mating portion 51 Fuel gas supply manifold hole 52 Coolant supply manifold hole 53 Oxidant gas supply manifold 54 Fuel gas discharge manifold hole 55 Coolant discharge manifold hole 56 Oxidant gas discharge manifold hole 60 Electrode peripheral part 61 Manifold hole peripheral part 62 Manifold hole peripheral part 63 Manifold hole peripheral part 64 Manifold hole peripheral part 65 Manifold hole peripheral part 66 Manifold hole peripheral part 70 Cell stack 71A End plate 71B End plate 72A Insulating plate 72B Insulating plate 73A Current collector plate 73B Current collector plate 81 Fuel gas supply passage 82 Cooling medium supply passage 83 Oxidant gas supply passage 84 Fuel gas discharge passage 85 Coolant discharge passage 86 Oxidant gas discharge passage 100 Polymer electrolyte fuel cell

Claims (7)

An electrolyte layer having an electrolyte layer and a pair of electrodes including a gas diffusion layer and a catalyst layer disposed between the gas diffusion layer and the electrolyte layer, with a portion excluding the peripheral portion of the electrolyte layer interposed therebetween. An electrode assembly;
A pair of annular gaskets disposed so as to surround each of the pair of electrodes of the electrolyte layer-electrode assembly;
A plate-like, and disposed, sandwiching the electrolyte layer-electrode assembly and the pair of gaskets, and a groove-like reaction gas flow channel is formed on one main surface contacting the electrode. A pair of conductive separators;
A polymer electrolyte fuel cell comprising: an oil absorber provided on at least a part of one main surface of the separator. At least a part of one main surface of the separator is provided with a groove,
The polymer electrolyte fuel cell according to claim 1, wherein the oil absorber is provided in the groove.   3. The polymer electrolyte fuel cell according to claim 1, wherein the oil absorber is provided in an outer portion than the catalyst layer on one main surface of the separator as viewed in the thickness direction of the separator. .   The polymer electrolyte fuel cell according to any one of claims 1 to 3, wherein the oil absorber is provided between the catalyst layer and the gasket.   3. The polymer electrolyte form according to claim 1, wherein the oil absorbing body is provided in at least a part of a portion of the one main surface of the separator facing the gasket as viewed from the thickness direction of the separator. Fuel cell.   6. The polymer electrolyte fuel cell according to claim 5, wherein the oil absorbing body is provided in an entire portion of the one main surface of the separator facing the gasket as viewed from the thickness direction of the separator.   2. The polymer according to claim 1, wherein the oil absorbent body is configured to include one or more substances selected from the group of substances consisting of polypropylene fiber, polyethylene fiber, polystyrene fiber, urethane foam, kapok fiber, and silica gel. Electrolytic fuel cell.

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